/*********************************************************************************
 *                                                                               *
 * The MIT License (MIT)                                                         *
 *                                                                               *
 * Copyright (c) 2015-2022 aoju.org OSHI and other contributors.                 *
 *                                                                               *
 * Permission is hereby granted, free of charge, to any person obtaining a copy  *
 * of this software and associated documentation files (the "Software"), to deal *
 * in the Software without restriction, including without limitation the rights  *
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell     *
 * copies of the Software, and to permit persons to whom the Software is         *
 * furnished to do so, subject to the following conditions:                      *
 *                                                                               *
 * The above copyright notice and this permission notice shall be included in    *
 * all copies or substantial portions of the Software.                           *
 *                                                                               *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR    *
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,      *
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE   *
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER        *
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, *
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN     *
 * THE SOFTWARE.                                                                 *
 *                                                                               *
 ********************************************************************************/
package org.aoju.bus.health.builtin.software;

import org.aoju.bus.core.annotation.ThreadSafe;

import java.util.List;

/**
 * The File System is a logical arrangement, usually in a hierarchial tree,
 * where files are placed for storage and retrieval. It may consist of one or
 * more file stores.
 *
 * @author Kimi Liu
 * @version 6.5.0
 * @since Java 17+
 */
@ThreadSafe
public interface FileSystem {

    /**
     * Get file stores on this machine
     * <p>
     * Instantiates a list of {@link OSFileStore} objects,
     * representing a storage pool, device, partition, volume, concrete file system
     * or other implementation specific means of file storage.
     *
     * @return A list of {@link OSFileStore} objects or an empty
     * array if none are present.
     */
    List<OSFileStore> getFileStores();

    /**
     * Get file stores on this machine
     * <p>
     * Instantiates a list of {@link OSFileStore} objects,
     * representing a storage pool, device, partition, volume, concrete file system
     * or other implementation specific means of file storage.
     *
     * @param localOnly If true, filters the list to only local file stores.
     * @return A list of {@link OSFileStore} objects or an empty
     * array if none are present.
     */
    List<OSFileStore> getFileStores(boolean localOnly);

    /**
     * The current number of open file descriptors. A file descriptor is an abstract
     * handle used to access I/O resources such as files and network connections. On
     * UNIX-based systems there is a system-wide limit on the number of open file
     * descriptors.
     * <p>
     * On Windows systems, this method returns the total number of handles held by
     * Processes. While Windows handles are conceptually similar to file
     * descriptors, they may also refer to a number of non-I/O related objects.
     *
     * @return The number of open file descriptors if available, 0 otherwise.
     */
    long getOpenFileDescriptors();

    /**
     * The maximum number of open file descriptors. A file descriptor is an abstract
     * handle used to access I/O resources such as files and network connections. On
     * UNIX-based systems there is a system-wide limit on the number of open file
     * descriptors.
     * <p>
     * On Windows systems, this method returns the theoretical max number of handles
     * (2^24-2^15 on 32-bit, 2^24-2^16 on 64-bit). There may be a lower per-process
     * limit. While Windows handles are conceptually similar to file descriptors,
     * they may also refer to a number of non-I/O related objects.
     *
     * @return The maximum number of file descriptors if available, 0 otherwise.
     */
    long getMaxFileDescriptors();

}
